Optical semiconductor devices are broadly classified into semiconductor light-emitting devices and semiconductor light-receiving devices.
In recent years, as a semiconductor light-emitting device, attention has been paid to a vertical-cavity surface-emitting laser (VCSEL) device in which an optical semiconductor structure including an active layer (light-emitting layer) is sandwiched between upper and lower membrane reflectors each composed of a photonic crystal.
With respect to such a semiconductor laser device, it is required that heat is dissipated efficiently therefrom, and less distortion generates within the device structure.